Monty M. Bodenheimer

Reversible asynergy. Histopathologic and electrographic correlations in patients with coronary artery disease.

Histopathologic-electrographic studies of ventriculography depicted nitroglycerin responsive and unresponsive asynergic areas were performed in 25 patients. Of 29 areas, 12 improved with nitroglycerin, showing < 10% muscle loss. Seventeen unimproved zones demonstrated significant fibrosis. Epicardial electrograms showed R waves in eight of nine improved zones. Of 11 unimproved zones, eight had Q waves.Histopathologic-electrographic data from five responders showed < 10% muscle loss, of whom four had epicardial R waves. Six unresponsive areas had significant fibrosis, with a QS over four.Thus, nitroglycerin responsive asynergic areas are generally comprised of histologically intact myocardium and are associated with epicardial R waves.

Detection of coronary heart disease using radionuclide determined regional ejection fraction at rest and during handgrip exercise: correlation with coronary arteriography.

SUMMARY The detection of regional asynergy provides strong evidence for a critical reduction of coronary blood flow to that zone. In the present study, the usefulness of combining computer-assisted radionuclide angiography and isometric handgrip exercise testing to detect coronary heart disease (CHD) was evaluated. One hundred twenty-nine patients with chest pain undergoing cardiac catheterization were evaluated using radionuclide angiography. Thirty-four patients were found to have severe contraction abnormalities during the initial radionuclide angiographic study. Of these, 33 had significant CHD. Ninety-five patients had normal or borderline normal left ventricular contraction and therefore underwent a second radionuclide angiogram during handgrip. Radionuclide angiogram data were quantitatively analyzed by computer to determine regional left ventricular contribution to ejection fraction during handgrip stress. Of the 95 patients, 30 had normal coronary arteries of whom 26 (87%) had normal relative regional ejection fraction. Sixty-five patients had CHD; 20 had single and 45 had two or three vessel obstructive disease. Of the 20 with single vessel disease, 16 (nine at rest and an additional seven during handgrip) had an area of decreased relative regional ejection fraction ranging from 31-87% in the corresponding segment during radionuclide angiography. Of the 45 patients with two or three vessel disease, 40 had regional abnormalities in ejection fraction during handgrip of from 31-100% (24 at rest and an additional 16 during handgrip). Moreover, 24 of these patients had multiple abnormalities in relative regional ejection fraction indicating multivessel disease. Overall, of the 95 patients who underwent isometric handgrip stress, sensitivity was 86% for detection of CHD and specificity was 87% for accurately defining the patients with normal coronary arteries.The results of the present study suggest that the radionuclide angiographic assessment of relative regional ejection fraction during isometric handgrip exercise may provide a useful new diagnostic approach for patients with suspected CHD as well as providing important additional data concerning its location and severity.

Determinants of Reversible Asynergy Effect of Pathologic Q Waves, Coronary Collaterals, and Anatomic Location

To determine which factors may be of value in determining whether or not asynergic zones have residual contractile ability, the responsiveness of these zones to sublingual nitroglycerin (1/150 grs) was studied angiographically in 36 patients. The responsiveness of asynergy was correlated with the presence or absence of pathologic Q waves and coronary collaterals in the corresponding zones, as well as with anatomic location. Of the 25 asynergic segments which had corresponding pathologic Q waves, 11 (44.0%) responded to nitroglycerin while 14 (56%) remained unresponsive. In contrast, 30 (83.3%) of the 36 segments which did not have associated Q waves improved while only 6 (16.4%) did not (P < 0.005). Akinetic segments with Q waves were associated with a significant decrease in responsiveness (P < 0.02) compared to hypokinetic segments. Of the 26 segments with angiographically demonstrable collaterals, 22 (84.6%) improved and only 4 (15.4%) remained unchanged (P < 0.02). In contrast, of the 35 segments without collaterals, 19 (54.3%) were responsive and 16 (45.7%) did not respond. Seven (77.8%) of the 9 akinetic segments with collaterals exhibited improvement compared to only 5 (33%) of the 15 segments without collaterals (P < 0.05). In segments with pathologic Q waves, 70% of those associated with collaterals improved compared to only 27% without collaterals (P < 0.02). Relative to anatomic location, of 29 anterior wall segments, 24 (82.8%) responded compared to only 11 (45.8%) of 24 apical segments (P < 0.005). These data indicate that the presence of coronary collaterals and absence of pathologic Q waves in the corresponding zones are associated with a higher incidence of residual contractile ability of asynergic segments. Apical asynergy responds less frequently than asynergy in other anatomic zones.

Comparative sensitivity of the exercise electrocardiogram, thallium imaging and stress radionuclide angiography to detect the presence and severity of coronary heart disease.

The relative sensitivity and specificity of individual and combined noninvasive tests to detect coronary heart disease were evaluated in 75 patients with chest pain admitted for cardiac catheterization and coronary arteriography. Of the 75 patients, 56 had coronary heart disease. Exercise-induced ST-segment abnormalities (>1 mm) were found in 58%. In contrast, computer-processed exercise thalliuim-201 perfusion imaging detected 82% (p < 0.01) and assessment of regional ejection fraction determined at rest and during isometric exercise by radionuclide angiography detected 82% (p < 0.02). Pathologic Q waves were present in 20%. Of nine patients with single-vessel disease, only one had exercise ST-segment abnormalities, while four had abnormalities in thallium-201 perfusion and five in regional ejection fraction. Of 16 patients with twovessel disease, 10 had ST-segment abnormalities, 14 had defects on thallium-201 imaging and 13 had abnormalities in regional ejection fraction. Similarly, of 31 patients with three-vessel coronary heart disease, 23 had exercise-induced ST-segment changes, while 28 had thallium-201 perfusion defects and 28 had abnormalities in regional ejection fraction. Combined noninvasive testing using pathologic Q waves and exercise ST-segment abnormalities detected 71% of patients with coronary heart disease. Addition of exercise thallium-201 imaging resulted in 88% of patients being detected, and addition of regional ejection fraction detected 96%. If an abnormality in any of the four tests was considered, 55 of 56 patients (98%) with coronary heart disease were detected. In 19 patients with normal coronary arteries, the specificity of the exercise ECG was 84%, exercise thallium-201 imaging 89% and assessment of regional ejection fraction 79%. However, if all noninvasive tests were considered, the specificity decreased to 58%. Thus, either exercise thallium-201 imaging or assessment of regional ejection fraction is superior to exercise-induced ST-segment abnormalities. Combined testing results in a very high sensitivity, but there is a concomitant reduction in specificity.

Q waves and ventricular asynergy: Predictive value and hemodynamic significance of anatomic localization

Two hundred sixteen consecutive patients were evaluated to determine the value of pathologic Q waves in predicting the presence and severity of ventricular asynergy. Of 64 patients with pathologic Q waves, 95 percent demonstrated asynergy. Q waves in the anterior leads denoted asynergy in 30 of 30 patients, anterior asynergy in 29 of 30 and an anterior aneurysm in 25. Q waves in the inferior leads indicated asynergy in 30 of 33 patients, inferior asynergy in 25 of 30 and an associated aneurysm in 19. Conversely, of 52 patients with an aneurysm, 44 also had pathologic Q waves. If Q waves were present, 72 percent of asynergic zones exhibited akinesis or dyskinesis; however, in the absence of Q waves an aneurysm was present in only 22 percent (P less than 0.0001). Hemodynamically, anterior asynergy, whether defined by Q waves or by ventriculography, was associated with more left ventricular dysfunction than was inferior asynergy (P less than 0.01). Of 21 patients with a cardiomyopathy, none had pathologic Q waves. The data indicate that pathologic Q waves can aid significantly in predicting the presence and location of a severely asynergic zone. Although their absence does not exclude the possibility of asynergy, the latter is much less likely and, if present, amy be of milder form.

Intervention ventriculography. Comparative value of nitroglycerin, post-extrasystolic potentiation and nitroglycerin plus post-extrasystolic potentiation.

The comparative value of nitroglycerin (TNG), postextrasystolic potentiation (PESP) and their combination (TNG + PESP) to unmask asynergic residual contraction was examined, each patient serving as his own control. Twelve of 13 hypokinetic zones improved both with TNG and PESP. One remained unchanged with either. Of 15 akinetic zones, four improved with both TNG and PESP, while ten remained unchanged. One akinetic zone, although improved with TNG, remained unchanged with PESP. Four dyskinetic zones did not change with either. Six asynergic zones responding to TNG alone demonstrated further augmentation with TNG + PESP. However, none of 13 TNG unresponsive zones improved with TNG + PESP. Thus, TNG, PESP, and TNG + PESP are each equally capable of unmasking asynergic residual contractile ability.

Relationship between regional myocardial perfusion and the presence, severity and reversibility of asynergy in patients with coronary heart disease.

SUMMARY In this study, the interrelationship of regional myocardial perfusion at rest and after exercise, the presence, severity and reversibility of asynergy and the severity of the corresponding coronary arterial obstruction was examined. Forty-five patients underwent exercise testing with thallium-201, cardiac catheterization including intervention (nitroglycerin) ventriculography and coronary arteriography. Of the 45 patients, 13 were normal by catheterization while 32 had coronary heart disease (CHD). Of the 32 with CHD, 21 had asynergy and 11 had normal ventricular contraction. Eighteen of 21 patients with asynergy also had a myocardial perfusion abnormality after exercise, while only three of the 11 without asynergy had a perfusion abnormality (P < 0.001). Of the 21 hypokinetic zones, only 67% had a myocardial perfusion abnormality, while all of the akinetic and dyskinetic zones had a perfusion defect (P < 0.025).Twenty-seven left ventricular zones demonstrated perfusion abnormalities after exercise, of which 19 had either normal or improved myocardial perfusion at rest. Fifteen of these 19 had reversible asynergy on nitroglycerin ventriculography while three had normal contraction. In contrast, the eight zones with myocardial perfusion defects, both at rest and with exercise, all had associated asynergy which was irreversible.A significant relationship was also observed between the severity of the coronary arterial obstruction, asynergy and a perfusion abnormality. Thus, of 39 myocardial zones supplied by 2 90% coronary arterial lesions, 24 had asynergy and 21 of these also had a corresponding myocardial perfusion defect. However, of the remaining 15 without asynergy, only three had a perfusion abnormality (P < 0.001). In addition, of 17 zones subserved by coronary vessels having 75-89% obstructive lesions, three of seven with asynergy had an associated perfusion abnormality, while none of the 10 without asynergy had a perfusion defect (P < 0.025).In summary, the findings of the present study indicate that there is a close interrelationship between the severity of a coronary arterial obstruction and both decreased regional myocardial perfusion and contraction in man. Myocardial perfusion, which is adequate at rest but abnormal with stress, is associated with less severe and reversible asynergy, while perfusion, which is abnormal even at rest, appears to be associated with more severe and irreversible asynergy.

Nuclear Cardiology . II . The Role of Myocardial Perfusion Imaging Using Thallium-201 in Diagnosis of Coronary Heart Disease

Since its introduction, thallium-201 has become the agent of choice in the clinical assessment of relative myocardial perfusion. Extensive evaluation has shown that it is of particular value in the diagnosis of coronary heart disease in patients with baseline S-T segment abnormalities or an inadequate heart rate response resulting in an inconclusive exercise electrocardiographic response. In addition, thallium-201 imaging is of value in the patient with a suspected false positive stress test; however, the definite incidence of false negative studies in patients with coronary heart disease tempers complete reliance on this approach. In the patient with a diagnostic exercise electrocardiographic stress test, thallium-201 provides limited additional information. Moreover, current techniques of analysis do not permit assessment of the number of coronary arteries with obstructive lesions. In the setting of acute myocardial ischemia, the role of thallium-201 is less clear. In acute myocardial infarction, the significant incidence of false negative responses combined with a multiplicity of potential causes of resting defects including severe but chronic coronary disease or unstable angina limits its diagnostic value.

Critical analysis of the application of bayes' theorem to sequential testing in the noninvasive diagnosis of coronary artery disease

The utility of Bayes theorem in the noninvasive diagnosis of coronary artery disease (CAD) was analyzed in 147 patients who underwent electrocardiographic stress testing, thallium-201 perfusion imaging and coronary angiography. Eighty-nine patients had typical anginal chest discomfort and 58 had atypical chest pain. Sensitivity and specificity of the tests and prevalence of CAD at each level of testing were tabulated and compared with the results generated from Bayes theorem. The sensitivity of electrocardiographic stress was higher in patients with multivessel CAD than in patients with 1-vessel CAD. Sensitivity, but not specificity, of each test was dependent, in part, on the result of the other test. However, the probabilities calculated from Bayes theorem when used for sequential testing are remarkably close to the tabulated data. Thus, Bayes theorem is useful clinically despite some evidence of test dependence. Sequential test analysis by Bayes theorem is most useful in establishing or ruling out a diagnosis when the pretest prevalence is approximately 50% and when the 2 tests are concordant.

Quantitative radionuclide angiography in the right anterior oblique view: comparison with contrast ventriculography.

Abstract Because the right anterior oblique view is widely accepted as the best “single” projection for assessing wall motion, the utility of this view during first pass radionuclide angiography was studied in 44 patients who also underwent contrast ventriculography and coronary arteriography. Of the 44 patients, 8 had a normal heart and 14 had coronary artery disease with normal wall motion on contrast ventriculography. All also had normal contraction on radionuclide angiography. On contrast ventriculography, 22 patients had coronary artery disease and asynergy involving 34 left ventricular segments. Of 17 segments localized to the anterior and apical asynergic areas on contrast ventriculography, 16 were accurately localized with radionuclide angiography. Similarly, of 17 inferior asynergic areas, 13 were also shown to be inferior on radionuclide angiography. In addition, quantitative assessment of the severity of asynergy using the hemiaxis method demonstrated a good correlation between asynergic severity as defined with radionuclide angiography and contrast ventriculography. Of 11 anterior areas, 7 defined as hypokinetic with contrast ventriculography demonstrated chordal shortening of 20.1 ± 5.2 percent (mean ± standard error of the mean) ( P P After appropriate background subtraction, determination of ejection fraction using radionuclide angiography showed a correlation of 0.839 between the left anterior oblique and right anterior oblique projections independent of the sequence of injection. In addition, ejection fraction determined with radionuclide angiography in the left ( r = 0.824) and right ( r = 0.801) anterior oblique views correlated well with ejection fraction assessed from contrast ventriculography. Thus, first pass radionuclide angiography performed in the right anterior oblique view is a sensitive noninvasive means of assessing the location and severity of asynergy as well as global left ventricular performance in patients with coronary artery disease.